Does anyone have a schematic for this amplifier?
It came in with both channels shorted and various 3904/3906 and 20 ohm resistors burned or shorted.
I replaced all needed parts but have full rail on both channels.
It came in with both channels shorted and various 3904/3906 and 20 ohm resistors burned or shorted.
I replaced all needed parts but have full rail on both channels.
I will start with the left channel (1) series.
Q119 was originally shorted.
I am having trouble trying to determine how rail is getting on this channel.
Replaced all output FET's in this channel.
Source resistors all test good.
Replaced Q120 and Q121.
Replaced R165 and R166.
I have checked in circuit various transistors and diodes. What am I missing?
Q119 was originally shorted.
I am having trouble trying to determine how rail is getting on this channel.
Replaced all output FET's in this channel.
Source resistors all test good.
Replaced Q120 and Q121.
Replaced R165 and R166.
I have checked in circuit various transistors and diodes. What am I missing?
If you touch a load across the speaker terminals, does the DC immediately drain off or does that cause a significant increase in current draw from the 12v supply?
Reading on R222 and Q201 are identical. Keep in mind both channels have the same issue, full rail voltage.
R122 has -14.23vdc and -8.18vdc
R222 has -22.50vdc and -28.40vdc
I measured R222 as a reference and its quite different.
R222 has -22.50vdc and -28.40vdc
I measured R222 as a reference and its quite different.
Post 11 and 17 conflict for the voltage on R122. Did you wait until the end of the initial mute delay?
R222 voltage need to be rechecked as well.
DCV across R119 and R219?
Confirm that both are within tolerance.
R222 voltage need to be rechecked as well.
DCV across R119 and R219?
Confirm that both are within tolerance.
I didnt wait for the mute delay.
R122 and R222 are within tolerance.
R122 reads 6.06 vdc across and at each end -14.23 vdc and -8.18 vdc
R222 reads 6.06 vdc across and at each end -14.24 vdc and -8.17 vdc
R119 and R219 are within tolerance.
R119 reads -0.142 vdc across and -14.50 vdc at each end.
R219 reads 0.152 vdc across and -14.50 vdc at each end.
Sorry for the confusion.
R122 and R222 are within tolerance.
R122 reads 6.06 vdc across and at each end -14.23 vdc and -8.18 vdc
R222 reads 6.06 vdc across and at each end -14.24 vdc and -8.17 vdc
R119 and R219 are within tolerance.
R119 reads -0.142 vdc across and -14.50 vdc at each end.
R219 reads 0.152 vdc across and -14.50 vdc at each end.
Sorry for the confusion.
Those numbers make more sense.
The R122 and R222 voltage may be a bit low.
DCV on all terminals of Q17 and Q18. One may be weak.
The R122 and R222 voltage may be a bit low.
DCV on all terminals of Q17 and Q18. One may be weak.